All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Allaah Says (what means): {O my father, indeed I fear that there will touch you a punishment from the Most Merciful so you would be to the devil a companion [in Hellfire].”}[Quran 19:45].
Ibn Al-Qayyim elaborated on the depth of the wisdom behind the kind words of Ibraaheem’s (Abraham) while addressing his father, in the aforementioned verse. He said: 'Ibraaheem attributed fear to himself rather than to his father, exactly in the same manner as a compassionate brother would do with someone about whom he is very concerned. Moreover, Ibraaheem selected the word 'touch' which is a word that is softer than other words, and then he stated the word ‘punishment’ in its indefinite form [indicating a lesser punishment impact]. He, further, chose the name of Allaah ‘the Most Merciful' and did not choose any other name such as 'the Compeller’ or ‘the Irresistible'. Thus, this was, indeed, a very kind and compassionate tone."
Furthermore, Ibn 'Aashoor in his interpretation of the above verse, said: 'After Ibraaheem established the fact that the worship of idols is but following the devil, he prophesized that the depravation of the Mercy of Allaah, and subsequently, suffering His torment will be the inevidable end for all idol worshippers.
Therefore, he warned him against being from the friends of the devil, since all people agree about their evilness and evil end. Moreover, to indicate that the reason of the punishment of Allaah results from being deprived of His Mercy, in this case, Ibraaheem chose the name of Allaah which includes the attribute of Divine Mercy to show that when the Most Merciful decides to punish someone, that this is a clear indication for the enormity of his crime; that his crime was so enormous to the extent that Allaah deprived him of His Mercy, in spite of, the vastness and unboundedness of His Mercy.”
Allaah Knows best.