Tirmidhi

(1) The verifier of the book has declared the mentioned narration as weak in terms of its chain of transmission, and has further written that some parts of this hadith have supporting narrations (shawahid) in Al-Mustadrak of Hakim and elsewhere, which Imam Hakim has declared authentic (sahih) and Imam Dhahabi has agreed with him. However, the verifier of the book himself has not passed any judgment on these supporting narrations, whereas other scholars have, most likely on the basis of these very supporting narrations, considered the mentioned narration to be hasan (good). In light of the evidence, their opinion appears to be closer to correctness. And Allah knows best. For further details, see: (Sahih Sunan an-Nasa'i by al-Albani: 2/68, no. 2035, and Dhakheerat al-Uqba Sharh Sunan an-Nasa'i: 20/43, 54)

(2) When Ibrahim (alayhis salam) came to know that his father had died upon disbelief, he abandoned seeking forgiveness (istighfar) for him. During his lifetime, it is permissible to supplicate for forgiveness and guidance for a polytheist, but not after he has died upon polytheism.