Is sincerity in seeking knowledge rewarded, and is it obligatory?

Sincerity in seeking knowledge is one of the greatest acts of worship. Sincerity to Allah Almighty is obligatory when seeking religious knowledge, based on the Prophet, peace and blessings be upon him, who said: "Whoever learns knowledge that should be sought for the sake of Allah Almighty, but he only learns it to gain some worldly benefit, will not find the fragrance of Paradise on the Day of Resurrection." And he said: "Whoever seeks knowledge to compete with scholars, or to argue with the foolish, or to attract people's attention to himself, Allah will admit him into the Fire." As for worldly knowledge, there is no objection to seeking it to obtain a job or money, and if one is sincere in it for the sake of Allah, it becomes an act of worship. Sincerity in these worldly sciences is obligatory for whoever for whom it has become an individual obligation (fard ayn).