Abu Salama bin 'Abdul Rahman and Ibn 'Abbas (RA) got together in the house of Abu Hurairah (RA) and began to discuss about the woman who gave birth to a child a few nights after the death of her husband. Ibn 'Abbas (RA) said: Her 'Idda is that period which is longer of the two (between four months and ten days and the birth of the child, whichever is longer). AbuSalama, however said: Her period of 'Idda is over (with the birth of the child), and they were contending with each other over this issue, whereupon Abu Hurairah (RA) said: I subscribe (to the view) held by my nephew (i. e. Abu Salama). They sent Kuraib (the freed slave of Ibn 'Abbas) to Umm Salamah to ask her about it. He came (back) to them and informed them that Umm Salamah (Allah be pleased with her) said that Subai'ah al-Aslamiyya gave birth to a child after the death of her husband when the few flights (had hardly) passed and she made mention of that to Allah's Messenger (ﷺ) and he commanded her to marry.
This hadith has been narated with the same chain of transrmitters except with a small change of words (and that is): They sent him to Umm Salamah, but no mention was made of Kuraib.
´It was narrated that Abu Salamah said:` "Ibn 'Abbas and Abu Hurairah were asked about the woman whose husband dies when she is pregnant. Ibn 'Abbas said: '(She should wait) for the longer of the two periods.' Abu Hurairah said: 'When she gives birth it becomes permissible for her to marry.' Abu Salamah went to Umm Salamah and asked her about that, and she said: 'Subai'ah Al-Aslamiyyah gave birth half a month after her husband died, and two men proposed to her. One was young and one was old, and she was inclined toward the young one. So the old one said: It is not permissible for you to marry. Her family was not there, and he hoped that if he went to her family they would marry her to him. She went to the Messenger of Allah and he said: It is permissible for you to marry, so marry whomever you want.'"
Hafiz Muhammad Ameen
One should not act with partiality in any fatwa or judgment on the basis of personal inclination. If there is a risk of bias, the judge (qadi) should not preside over the case; rather, another judge who can decide impartially should hear the case.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 3540
´Abu Salamah bin 'Abdur-Rahman said:` "It was said to Ibn 'Abbas concerning a woman who gives birth one day after her husband died: 'Can she get married?' He said: 'No, not until the longer of the two periods has ended.' He said: 'Allah says: And for those who are pregnant (whether they are divorced or their husbands are dead), their 'Iddah (prescribed period) is until they lay down their burden.' He said: 'That only applies in the case of divorce.' Abu Hurairah said: 'I agree with my brother's son' --meaning, Abu Salamah. He sent his slave Kuraib and told him: 'Go to Umm Salamah and ask her: Was this the Sunnah of the Messenger of Allah?' He came back and said: 'Yes, Subai'ah Al-Aslamiyyah gave birth twenty days after her husband died, and the Messenger of Allah told her to get married, and Abu As-Sanabil was one of those who proposed marriage to her.'"
Hafiz Muhammad Ameen
Urdu marginal note: Ibn Abbas radi Allahu anhu was of the opinion that the waiting period (iddah) of mourning is obligatory in every case, as well as the completion of childbirth (for a pregnant widow). However, since the statement of the Messenger of Allah sallallahu alayhi wa sallam was different from this, Ibn Abbas radi Allahu anhu retracted his opinion. Radi Allahu anhu wa ardaahu.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 3541