His mother told him not to observe the fast of Dawud (peace be upon him) for a few days; should he obey her?
Question

Allah has enabled me to fast alternate days. On Fridays, my family meets for breakfast and everyone has to attend. Because I am fasting sometimes, I do not attend, because the day on which I am fasting coincides with Friday in the first week and does not coincide with it in the second week, and so on… This upsets my mother, as she wants everyone to attend and not be absent. She says to me: Do not fast on Friday, and fast for two days after that if you want. Can I do what my mother is telling me to do, without missing out on the reward for fasting alternate days?
Praise be to Allah.Our advice to you is to obey your mother, and do not fast on Friday when you are with your family, then you can fast for two days after that, and there is the hope that you will have the reward of observing the fast of Dawud, because when ‘Abdullah ibn ‘Amr (may Allah be pleased with him) became unable to fast alternate days in his old age, he began to not fast for a few days, then he would make them up by fasting the same number of days consecutively.
Al-Bukhari narrated in his Sahih (5052) that ‘Abdullah ibn ‘Amr (may Allah be pleased with him) said: My father arranged my marriage to a woman from a noble family. He used to visit his daughter-in-law and ask her about her husband, and she would say: What a good man he is! He never comes to my bed, nor has he approached me since he married me. When had gone on for a long time, he mentioned that to the Prophet (blessings and peace of Allah be upon him) who said: “Let me meet him.” Then I met him and he said: “How do you fast?” I said: [I fast] every day. He said: “How long does it take you to complete the recitation of the Qur’an?” I said: “[I complete it] every night. He said: “Fast for three days every month and complete the Qur’an once a month.” I said: I am able to do more than that. He said: “Fast for three days every week.” I said: I am able to do more than that. He said: “Do not fast for two days and fast for one day.” I said: I am able to do more than that. He said: Observe the best of fasts, the fast of Dawud, fast one day and not the next. And recite [complete the Qur’an] once in every seven nights.” Would that I had accepted the concession of the Messenger of Allah (blessings and peace of Allah be upon him), for I have grown old and weak. He used to recite one seventh of the Qur’an to some of his family members during the day, by way of practising it during the day, so that it would be easier for him when reciting at night. And if he wanted to gain some strength, he would stop fasting for a few days and count those days, then fast the same number of days, because he did not like to give up something that he used to do during the lifetime of the Prophet (blessings and peace of Allah be upon him).
I put this question to our shaykh, ‘Abd ar-Rahman ibn Barrak, may Allah preserve him, and he said:
The aim was to fast half of the time, so if he did not fast, he would fast the same number of days later on.
And Allah knows best.