وَإِذْ تَأَذَّنَ رَبُّكُمْ لَئِن شَكَرْتُمْ لَأَزِيدَنَّكُمْ ۖ وَلَئِن كَفَرْتُمْ إِنَّ عَذَابِي لَشَدِيدٌ

This verse presents a divine promise and warning regarding gratitude and ingratitude. Allah promises to increase His blessings for those who are grateful, while warning of severe punishment for those who are ungrateful. Gratitude (shukr) involves recognizing Allah as the source of all blessings, expressing thanks through words and actions, and using blessings in ways that please Allah. The "increase" promised can be in the same blessings or different ones, and may include spiritual blessings that are even more valuable than material ones. Ingratitude (kufr) here refers to denying Allah's favors or attributing them to other sources. This verse teaches that gratitude is a key to receiving more blessings, that recognition of Allah's favors leads to their multiplication, and that ingratitude leads to loss of blessings and divine displeasure. It encourages believers to cultivate thankfulness as both a spiritual practice and a practical means of attracting more divine favor.