And when He reminded them of the blessing of security, He encouraged them to increase it and warned them against what would remove it. He said: "And when" meaning remember when ﴿Your Lord proclaimed﴾, that is, He informed the benefactors towards you with a clear announcement that removes any doubts, saying: ﴿If you are grateful﴾. He emphasized this because of the tendency of souls to deny such a thing, due to their belief that increase comes from striving for sustenance and decrease comes from negligence in it. ﴿I will surely increase you﴾ of My blessings. For indeed, gratitude is the restraint of what exists and the capture of what is missing. "Indeed, My gift is surely abundant, so hope for it." (p-385) ﴿And if you deny﴾ the blessing and do not restrain it with gratitude, I will surely decrease you and I will surely punish you. ﴿Indeed, My punishment﴾ by removing it and other things ﴿is severe﴾, so fear it. The verse, as you see, is from the style of interweaving.