Allah commands His believing servants to remember their Lord much, Who has bestowed upon them all kinds of blessings and favors, because this will bring them a great reward and a wonderful destiny. Imam Ahmad recorded that `Abdullah bin Busr said: "Two bedouins came to the Messenger of Allah ﷺ and one of them said: `O Messenger of Allah, which of the people is best' He said:
«مَنْ طَالَ عُمْرُهُ وَحَسُنَ عَمَلُه»
(The one whose life is long and whose deeds are good.) The other one said: `O Messenger of Allah, the laws of Islam are too much for us. Teach me something that I can adhere to.' He said,
Sayyidna Ibn ` Abbas ؓ has stated that Salah from Allah is blessing, from angels it is prayer for forgiveness and from humans it is supplication. The word Salah carries all the three meanings.
تَحِيَّتُهُمْ يَوْمَ يَلْقَوْنَهُ سَلَامٌ (Their greeting, the Day they will meet Him, will be, "Salam" - 33:44). This is the explanation of the Salah that is sent to believers from-Allah. It means that the day they would meet Allah, they will be respectfully addressed by Him with the word, 'Salami i.e. (Assalamu ` alaykum) . The day of meeting Allah according to Imam Raghib, would be the Doomsday; some other leading exegetes say that it would be when they enter Paradise and they would receive Salam from Allah Ta’ ala as well as from the angels; and yet other scholars consider it to be the day of death when they would leave the whole world to be present before Allah as stated by Sayyidna ` Abdullah Ibn Masud ؓ that when the Angel of Death goes to a believer to extract the spirit of life out of him, he gives him a message that his Lord has sent to him Salam. The word 'meeting' is true in all the three cases. Therefore there can be no objection or contradiction in the traditions, because Salam from Allah Ta’ ala is sent on all the three occasions.
Note
This verse has proved that when Muslims meet each other, their greeting should be assalamu ` alaykum whether from the older to the younger or from the younger to the older.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 44–47
When an adulterated religion is dominant, the adoption of true religion is always the most difficult task. Under such circumstances, the hearts of the faithful sometimes harbour feelings of dejection and disappointment. There is one certain method of saving oneself from this and that is to keep looking for the silver lining in the dark clouds. Common people live on the strength of materialism, while the Faithful live on the strength of ideas. To live on the level of ideas means that a man lives for the remembrance of God. The angels’ inaudible discourse should be audible to him. He should give the utmost importance to his intellectual and spiritual development.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.