Imam Abu Amr Al-Awza’i {May Allah have mercy upon him} said:
تعلم ما لا يؤخذ به, كما تعلم ما يؤخذ به
“Learn that which will not be relied upon, just as you learn that which will be relied upon.”
{Tarikh Ibn ’Asakir, 35/186}
And he {May Allah have mercy upon him} said:
عن الأوزاعي قال طالب العلم بلا سكينة ولا حلم كالإناء المنخرق كلما حمل فيه شئ تناثر
“A student of knowledge who has no tranquility and no patience is like a punctured container, whenever something is carried in it vanishes.”
{Tarikh ibn ‘Asakir, 35/185}