Aisha reported: The Messenger of Allah, peace and blessings be upon him, entered while I was with another woman. The Prophet asked, “Who is this?” I said, “She is a woman who never sleeps because she is always praying.” The Prophet said, “You must only perform deeds if you are capable . By Allah, Allah will not withhold from you until you give up. The most beloved religion to Allah is one which is performed regularly.”

Source: Sahih Bukhari 43, Sahih Muslim 785

Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim

عَنْ عَائِشَةَ قَالَتْ دَخَلَ عَلَيَّ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَعِنْدِي امْرَأَةٌ فَقَالَ مَنْ هَذِهِ فَقُلْتُ امْرَأَةٌ لَا تَنَامُ تُصَلِّي قَالَ عَلَيْكُمْ مِنْ الْعَمَلِ مَا تُطِيقُونَ فَوَاللَّهِ لَا يَمَلُّ اللَّهُ حَتَّى تَمَلُّوا وَكَانَ أَحَبَّ الدِّينِ إِلَيْهِ مَا دَاوَمَ عَلَيْهِ صَاحِبُهُ

43 صحيح البخاري كتاب الإيمان باب أحب الدين إلى الله عز وجل أدومه

785 صحيح مسلم كِتَاب صَلَاةِ الْمُسَافِرِينَ وَقَصْرِهَا لا تنام الليل خذوا من العمل ما تطيقون فوالله لا يسأم الله حتى تسأموا

http://dailyhadith.abuaminaelias.com/2012/08/01/hadith-on-moderation-allah-loves-regular-good-deeds-even-if-they-are-small-so-do-not-overburden-yourself-with-worship/