It was narrated that Masruq and 'Amr bin 'Utbah wrote to Subai'ah bint Harith, asking about her case.:
She wrote to them saying that she gave birth twenty-five days after her husband died. Then she prepared herself, seeking to remarry. Abu Sanabil bin Ba'kak passed by her and said: "You are in a hurry; observe waiting period for the longer period, four months and ten days." "So I went to the Prophet (ﷺ) and said: 'O Messenger of Allah, (ﷺ) pray for forgiveness for me.' He said: 'Why is that." I told him (what had happened). He said: 'If you find a righteous husband then marry him."'
English reference: Vol. 3, Book 10, Hadith 2028
Arabic reference: Book 10, Hadith 2106