What is the difference between the Quranic expression "bi muhlik" (بمهلك) in Surat Al-An'am and "li yuhlika" (ليهلك) in Surat Hud when speaking of the destruction of towns due to their injustice?

The exegetes did not differentiate between the negation of destruction in verses 131 of Al-An'am and 117 of Hud. However, the negation of destruction in the first verse (Al-An'am) is preceded by the sending of messengers, whereas its negation in the second verse (Hud) is perpetual, provided that the people of the towns are reformers. Therefore, the lām al-juḥūd (negation lām) was used with it, as it is more emphatic in negation.