The Importance of Having Intention Present When Performing an Act

Question:
Also, the motivation for this question is followed by another question related to and connected with intention. He says: If I perform a good deed, and the intention to seek reward does not come to me until after a period of time, which may be long, have I earned the reward, or must the intention be present during and at the time of performing the act?

Answer:
The intention must be with the act. The Messenger (peace and blessings be upon him) said: So the intention must be with the act, concurrent with the act. If one performs the act without intention, and then intends it afterwards, that intention does not benefit him. Suppose, for example, that he prayed, bowed, prostrated, stood, and did the actions of prayer, but he did not intend the prayer. Then, after he finished, he intended it to be an obligatory or voluntary prayer. It does not suffice for him and does not benefit him because it was devoid of intention.
Suppose, for example, that he bathed with water while in a state of major ritual impurity. He bathed with water without intention, and then, after he finished, he intended it to be for the major ritual impurity. That does not benefit him. The Messenger (peace and blessings be upon him) said: Likewise, if he performed ablution, washing the limbs of ablution, but without the intention of ablution, and then intended it afterwards, it does not suffice for him regarding ablution because it was devoid of intention. So the intention is what makes the act valid. Yes.