Concerning Allah's statement,

لَا يَسْمَعُونَ فِيهَا لَغْوًا ...

They shall not hear therein any Laghw.

This means that in these gardens of Paradise there is no ignorant, wasteful and useless speech, like there is in this life.

He said,

... إِلَّا سَلَامًا ...

...but only Salam.

This is an indifferent exception, similar to Allah's statement,

لاَ يَسْمَعُونَ فِيهَا لَغْواً وَلاَ تَأْثِيماً

إِلاَّ قِيلاً سَلَـماً سَلَـماً

No Laghw will they hear therein, nor any sinful speech. But only the saying of: Salam! Salam! (56:25-26)

Concerning His statement,

... وَلَهُمْ رِزْقُهُمْ فِيهَا بُكْرَةً وَعَشِيًّا ﴿٦٢﴾

And they will have therein their sustenance, morning and afternoon.

This means, in what is similar to mornings and evenings. This does not mean that there is a night and a day (in Paradise), but they will be living in times that alternate. They will know its lighted times from its lights and illumination.

This is as Imam Ahmad recorded from Abu Hurayrah, who said that the Messenger of Allah said,

أَوَّلُ زُمْرَةٍ تَلِجُ الْجَنَّةَ صُوَرُهُمْ عَلَى صُورَةِ الْقَمَرِ لَيْلَةَ الْبَدْرِ لَا يَبْصُقُونَ فِيهَا،وَلَا يَتَمَخَّطُونَ فِيهَا. وَلَايَتَغَوَّطُونَ، آنِيَتُهُمْ وَأَمْشَاطُهُمُ الذَّهَبُ وَالْفِضَّةُ وَمَجَامِرُهُمُ الْأَلُوَّةُ، وَرَشْحُهُمُ الْمِسْكُ وَلِكُلِّ وَاحِدٍ مِنْهُمْ زَوْجَتَانِ، يُرَى مُخُّ سَاقِهَا مِنْ وَرَاءِ اللَّحْمِ مِنَ الْحُسْنِ، لَا اخْتِلَافَ بَيْنَهُمْ وَلَا تَبَاغُضَ، قُلُوبُهُمْ عَلَى قَلْبِ رَجُلٍ وَاحِدٍ، يُسَبِّحُونَ اللهَ بُكْرَةً وَعَشِيًّا

The first group to enter into Paradise will have forms like the form of the moon on a night when it is full. They will not spit, nor will they blow their noses therein. They also will not defecate. Their containers and combs will be made of gold and silver and their censers will be of aloes wood. Their sweat will be the fragrance of musk and each of them will have two wives. The marrow of their shins will be visible from beneath the skin due to their beauty. They will not have any disputes between them, or any hatred. Their hearts will be united like the heart of one man. They will glorify Allah in the morning and evening.

Al-Bukhari and Muslim both recorded this narration in the Two Sahihs.

Imam Ahmad also recorded that Ibn Abbas said that the Messenger of Allah said,

الشُّهَدَاءُ عَلَى بَارِقِ نَهْرٍ بِبَابِ الْجَنَّةِ فِي قُبَّةٍ خَضْرَاءَ، يَخْرُجُ عَلَيْهِمْ رِزْقُهُمْ مِنَ الْجَنَّةِ بُكْرَةً وَعَشِيًّا

The martyrs will be upon the banks of a river by the gates of Paradise. Over them will be a green dome. Their sustenance will be brought out to them from Paradise, morning and evening.

Ahmad is the only one who collected this narration.

Ad-Dahhak reported that Ibn Abbas said, وَلَهُمْ رِزْقُهُمْ فِيهَا بُكْرَةً وَعَشِيًّا (And they will have therein their sustenance, morning and afternoon),

"This means the amount of time equal to night and day.''