Reaching back to the Prophet ﷺ, he said, "The strong believer is better and more beloved to Allah than the weak believer, though there is good in both. Strive for what benefits you, and do not be helpless. If something overcomes you, say, 'Allah has decreed, and He does as He wills.' Beware of saying 'if only,' for 'if only' opens the door to the work of Satan."
حدثنا محمد بن الصباح أنبأنا سفيان بن عيينة عن ابن عجلان عن الأعرج
يبلغ به النبي ﷺ قال المؤمن القوي خير وأحب إلى الله من المؤمن الضعيف وفي كل خير احرص على ما ينفعك ولا تعجز فإن غلبك أمر فقل قدر الله وما شاء فعل وإياك واللو فإن اللو تفتح عمل الشيطان
[Sahih] Nasai reported it in Al-Kubra 6/159, no. 10457, from the hadith of Sufyan, with this chain. Muhammad bin Yahya bin Habban also narrated it from Araj with this chain, and it was reported by Muslim, no. 2664, and Ibn Majah, see no. 79. Ibn Ajlan and others have other variant versions.