Tafsir of Al-Isra 17:25

(Of the intention of righteousness and the formation of the veneration owed to them). It is said that this is a threat against harboring hatred or finding them burdensome. It is stated in al-Kashshaf that it serves as a justification for the emphasis placed upon treating parents with excellence, for Allah Almighty knows what is in their inner selves of that [intention], and will recompense them accordingly.

The apparent meaning is that it is a promise for the one who harbors righteousness and a threat for others, though the latter aspect is predominant because the address is primarily concerned with it.

(If you are righteous) — meaning: intending righteousness and goodness, rather than disobedience and corruption — (then indeed He) — Glorified is His status — (is ever, to the oft-returning to Him, Forgiving). That is, to those who return to Him, repenting from what has transpired from them, which is something that human beings can hardly avoid.

(Forgiving) — of the type of shortcoming or harm that has occurred on their part. As noted in al-Kashshaf, this is an easing after emphasis and stringency, alongside restriction and warning. This is because He made the condition for the impulsive slip—which occurs rarely—to be the intent of righteousness, expressing it as righteousness itself. He did not explicitly state that it [the slip] occurred, but rather alluded to it by His saying: (then indeed He is ever, to the oft-returning to Him, Forgiving), for forgiveness necessitates the existence of a sin, as does the term "oft-returning," for repentance from a sin is conditioned upon the intent of righteousness and sincere repentance from it as well.

This is a second initiation required by the context of emphasis and intensity, as if it were said: "How can we fulfill their rights when impulsive slips may rarely occur?" It was replied: "If you build the matter upon this foundation and this is your continuous state, then if a slip occurs without the intent of causing harm, the gentleness of Allah Almighty will shield you from His punishment, remaining vigilant [over you]."

The interpretation that the verse concerns the slip occurring from a man toward his parents is narrated from Ibn Jubayr. It is also permitted that it be general for every repentant person, with the one who commits an offense against his parents and repents from it being included primarily.