The Commander of the Faithful, Sayyiduna Umar ibn al-Khattab (may Allah be pleased with him) said: Learn the obligatory duties, the rules, and the Sunnahs just as you learn the Qur'an.
Hadith Referenceسنن دارمي / من كتاب الفرائض / 2884
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده صحيح وهو موقوف على عمر رضي الله عنه، [مكتبه الشامله نمبر: 2892]
Hadith Takhrijاس روایت کی سند صحیح ہے اور یہ قول موقوف على سیدنا عمر رضی اللہ عنہ ہے، اس کو ابن ابی شیبہ نے [مصنف 459/10، 9975] میں اور سعید بن منصور نے [السنن 1] میں اور [البيهقي 209/6] نے ذکر کیا ہے۔
Brief Explanation
(Commentary on Hadith 2883)
By "faraid" is meant inheritance, its shares, and its rulings; by "lahn" is meant the rules and regulations of Arabic grammar (nahw), so that one does not make mistakes in speaking and understanding the Arabic language; and by "sunan" is meant the sayings of the Messenger (sallallahu alayhi wa sallam) and the science of hadith. In reality, a person is in utmost need of these three sciences.
Although this is the statement of Sayyiduna Umar (radi Allahu anhu), it is not possible to deny the importance of these sciences.