Hadith 2957
Abdur Rahman bin Mu’qil said: Sayyiduna Ibn Abbas (may Allah be pleased with them both) was asked about the grandfather, so he said: Who is the greatest among your fathers (grandfathers)? (And in another narration: When the questioner could not answer,) I said: Adam (is the greatest father). He replied: Have you not heard the saying of Allah Almighty: "O children of Adam"?
Hadith 2958
Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: I wish that (regarding the grandfather) I and the one who opposes me would invoke a curse upon each other, that the one whose statement is incorrect (i.e., may the curse be upon the one whose statement is incorrect).
Hadith 2959
Sayyiduna Ibn Abbas (may Allah be pleased with them both) considered the grandfather as the father.