The Description of the Gardens of the Truthful and Those Who repent
Allah, the Exalted, says that the Gardens (of Paradise), which the penitent will enter, will be Gardens of `Adn, meaning, eternity. These are Gardens that the Most Beneficent promises His servants in the unseen. This means that these Gardens are from the unseen things that they believe in, even though they have never witnessed them. They believe in the unseen out of their strong conviction and the strength of their faith. Concerning Allah's statement,
إِنَّهُ كَانَ وَعْدُهُ مَأْتِيّاً
(Verily, His promise must come to pass.) This affirms the fact that this will occur, and that it is a settled matter. Allah does not break His promise, nor does He change it. This is similar to His statement,
"They will not hear anything absurd therein but a word of peace." - 19:62.
(لَغو) means idle, absurd, frivolous and abusive talk, which will not reach the ears of good people who have been admitted to Paradise.
إِلَّا سَلَامًا means that whatever one will hear in Paradise will add to his happiness, peace and tranquility. It includes the customary greetings (سَلَام), which the dwellers of Paradise will exchange among themselves and the angels of God will offer them all. (Qurtubi)
وَلَهُمْ رِزْقُهُمْ فِيهَا بُكْرَةً وَعَشِيًّا
"And there they will have their provisions at morn and eve." - 19:62.
There will be no solar system in the Paradise and hence no rising or setting of the sun, but there will be a perpetual radiance. There will also be some way of telling day from night and morning from evening. Within this distinction between morning and evening the Paradise dwellers will receive their meals. It goes without saying that the wishes of the Paradise dwellers will be fulfilled forthwith وَلَهُم مَّا يَشْتَهُونَ - and for themselves, there is what they desire - 16:57). This is a general announcement. Hence, mention of morning and evening is because of people's habit to eat and drink in the morning and in the evening. According to an Arab saying, anyone who gets a full meal morning and evening is comfortable and at peace.
Sayyidna Anas Ibn Malik ؓ ، said after reciting this verse that it shows that the believers have their meals twice a day, one in the morning and the other in the evening.
Some scholars have explained that mention of morning and the evening is a general expression, like day and night or east and west, which does not specify any particular time or place. Therefore, it means that they (Paradise dwellers) will get their provisions according to their choice at any time they like. (Only God knows best) (Qurtubi)
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 60–62
A distinctive trait of those whose characters are moulded by the preaching of the prophets, is that they are no longer slaves of their base desires but rise above them. They turn into individuals who always remember God; indeed, the essence of religion is remembrance of God, the organized expression of which is prayer (salat). If the generations that come after the prophets become negligent of God and start following their base desires, they will figure, in the eyes of God, as people who have gone astray. Being affiliated to a prophet shall be of no use to them. They shall receive what they deserve. Of them, only those shall be spared who return to the original religion, and adopt a life of faith and virtuous deeds. Those who strive for the life Hereafter, do not immediately receive the fruits of their labours and sacrifices. For this reason, they may have misgivings that this is a path of pointless endeavour. But this is a mere misunderstanding. The fact is that, just as those who devote their efforts to worldly affairs achieve corresponding results, so also will those who strive for the life of the Hereafter be requited in full measure. Nobody need harbour any doubts about this.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.