And carry out the Hajj and the Umrah for God. But if you are prevented, then whatever is feasible of offerings. And do not shave your heads until the offering has reached its destination. Whoever of you is sick, or has an injury of the head, then redemption of fasting, or charity, or worship. When you are secure: whoever continues the Umrah until the Hajj, then whatever is feasible of offering. But if he lacks the means, then fasting for three days during the Hajj and seven when you have returned, making ten in all. This is for he whose household is not present at the Sacred Mosque. And remain conscious of God, and know that God is stern in retribution.

The Holy Quran · Al-Baqara (The Cow) · 2:196