In The Name of Allaah, The Most Merciful, The Bestower of Mercy
The most beloved worship to Allaah is that which is constant, for indeed the one who imposes upon himself that which is beyond his ability [i.e. extra supererogatory acts of worship] which he might not able to do, it is inevitable that his strength will disappear gradually, so he becomes weak or might even deviate, because he imposed upon himself that which is beyond what he can do [i.e. extra supererogatory acts of worship which he cannot do], deprived his [body] of its rights, his family and others. [Salmaan (radiyallaahu anhu) said to Abu Dardaa (radiyallaahu anhu)]: “Your Lord has rights on you, your ownself has a right on you, and your family has rights on you, so you should give the rights to all those who have a right on you.” [Bukhaari 1968]
Abdullaah Ibn Umar [radiyallaahu anhumaa] used to fast constantly without a break and completed recitation of the Qur’aan every night, so Allaah’s Messenger [sallal laahu alayhi wasallam] clarified for him and said: “It is sufficient for you to fast for three days a month”, so he said, “I can do more than that.” The Prophet [sallal laahu alayhi wasallam] said, “Your wife has a right on you, your guest has a right on you and your body has a right on you….so fast [in the manner that] Allaah’s Prophet Dawood used to fast” [i.e. alternative days] [Bukhaari 6134]
Therefore, balance worship [i.e. related to extra optional acts of worship based on one’s ability and prevents one from neglecting the rights his wife, body etc] preserves a person’s strength and enables him to be constant in worship.
Marhaban Yaa Taalibal Ilm’ page 242. slightly paraphrasedw