If a fasting person eats, drinks, or has sexual relations forgetfully before the intention in Ramadan, it does not invalidate their fast according to the correct opinion, as stated in Al-Durr Al-Mukhtar 2: 97. Forgetfulness is considered a barrier to the invalidation of the fast in all cases; thus, whoever does any of the invalidating actions forgetfully does not break their fast, whether the fast is obligatory or voluntary, and whether the invalidation occurred before or after the intention in Ramadan. Abu Huraira (may Allah be pleased with him) reported that the Prophet (peace be upon him) said: "Whoever eats forgetfully while fasting, let him complete his fast, for what he has been fed and given to drink is from Allah." This is found in Sahih Al-Bukhari 6: 2455, Sahih Muslim 2: 809, and Al-Muntaka 1: 105. Abu Huraira (may Allah be pleased with him) also reported that the Prophet (peace be upon him) said: "Whoever breaks their fast in the month of Ramadan forgetfully, there is no expiation upon them and no compensation." This is found in Sahih Ibn Hibban 8: 287, Al-Mustadrak 1: 595 (and it was authenticated), and Ibn Hajar authenticated it in Bulugh Al-Maram. See: I'laa Al-Sunan 9: 130.