Guide
Understand what you recite in salah
Ghazali ties presence of heart to knowing what you are saying. Start by giving the words time.
Understand what you recite in salah, and the prayer stops being a password. Abu Hamid al-Ghazali, in Ihya' Ulum al-Din, The Mysteries of Prayer, puts understanding among the things that serve presence of heart (hudur al-qalb). He also says presence comes when causes of distraction are cut beforehand, and that the inattentive prayer is not remembrance. A person can cut the phone and bare the room and still recite a language he has never sat with. The mouth will finish. The heart will not have been addressed.
This is not a shame sentence for someone who grew up with sound and no translation. That is a common history. The work is available now. It does not require becoming a mufassir before Maghrib. It requires that the next recitation be slow enough to be speech, and that speech eventually be known. Tonight's practice, on this site, is the first of those: slow recitation.
Why speed blocks understanding
You cannot understand at a pace that treats the ayah as a hurdle. The mind needs a little room to hear that a sentence has a subject and a request. Halving the speed is how a memorized surah becomes audible to its owner. This is already a treatment here. It adds under two minutes. People who say they want to understand what they recite, then race, are asking for a result they will not make space for.
A servant may have only a tenth of the prayer written (Abu Dawud). Haste is one of the ways a prayer shrinks. Understanding shrinks with it. You do not need a new hadith for that. You need to notice that your “I want to concentrate in namaz” and your “I want to know the meaning” are often the same problem: the words never get to be words.
What understanding is, and is not
It is not a feeling. You can know that “iyyaka na'budu” is a restriction of worship to Allah and still feel nothing. Knowledge is not khushu. It is one of khushu's supports. Ibn al-Qayyim names khushu as the heart standing before Allah, when the heart is emptied for the prayer and the prayer is preferred to everything else. Understanding helps the standing because the heart is no longer repeating sounds that belong to someone else. It does not force the standing.
It is not a project to finish the whole mushaf's vocabulary this month. Ghazali's instruction is about what you say, which, for most prayers, is a short set of words you already repeat every day. Start there. Al-Fatiha. The short surah you actually use. The tasbih in ruku and sujood. If you do not know those, you do not need a bigger plan.
The book has a practice of living with one ayah of al-Fatiha per week. This guide will not assign it, because the allowed next steps for these pages are the six already listed. Know that the longer work exists. Do the slowness first, so there is somewhere for a meaning to land when you later sit with a line.
Cut the other noise so a meaning can enter
Understanding will not survive a feed in the pocket. The phone out of the room is still Ghazali's cutting of causes. A bare room, or a gaze fixed at the place of sujood, is the same cutting for the eyes. People try to study a translation with the same attention they bring to a notification. That study does not reach the salah. The salah is a different room. Prepare it as a room.
Two minutes of stillness before takbir gives the translation, if you read one, a place to settle. You do not review notes on the mat. You stand. You let the day quiet. Then you say words you have decided to say slowly. That is enough method for a week.
When you already know the meaning and still feel nothing
Knowing is not the same as presence. Many people who can explain al-Fatiha still lock the door with it five times a day. If that is you, the problem is not information. It is habit, speed, and the heart's rivals. See the guide on khushu after years of habit. Do not collect more meanings as a way of avoiding the two minutes of stillness.
The Qur'an says the prayer is for remembrance (20:14) and warns against heedlessness (7:205). Remembrance includes knowing what is being said. Heedlessness includes saying it without that knowing, and also knowing it without standing still. Both are possible. Both are ordinary. Neither is a reason to stop.
Named source
Abu Hamid al-Ghazali, Ihya' Ulum al-Din, The Mysteries of Prayer: understand what you say. Presence of heart comes when causes of distraction are cut beforehand. The inattentive prayer is not remembrance. Paraphrase of the argument. No invented quotation.
One practice
Next step
Slow the recitation in the next salah. Halve your speed so the words have room to be words. This is the practice already on this site. If you know a meaning, let it arrive at that slower pace. If you do not, the slowness is still the right first work. Look up one line after taslim, not during it.
Related sentence: “I read Qur'an and nothing happens.”