What does the hadith:” The best deed is waiting for relief” mean? Some people assume and think that “waiting the relief, which is the best deed, means to wait for the reappearance of Imam Al Mahdi (ajtf), his close friends and supporters who are “313” man to fight the enemies of Islam and purify the earth from their dirtiness. They will spread justice and security in the country and provide the perfect manifestation of luxury and freedom. After that they say to us: Come in, if you please!
Some assume that this is how they wait for relief. They describe it as the best deed. But in reality, the true meaning of waiting for the relief is waiting for the reappearance of Al Imam (a.s) to be a part of his army and fight according to his commands even if we are martyred at the end. The true waiting is when all of man’s hope depends on fighting for the sake of God. It is surely not about waiting for Al Hujja (ajtf) to tell him: go alone, accomplish all the tough missions, and we will be there waiting for you to gather the spoils. This is how Moses friends behave, while Muhammad’s friends told him: O God’s prophet! We don’t tell you what children of Israel told Moses when they arrived in Palestine-Jerusalem- and saw the prepared soldiers. They said:” Go, you and your Lord, to fight. We will stay here”. 
This is how Moses' friends behaved. They asked him to go, fight for Palestine, clean his land from the dirtiness of enemies, then they will come after assuring that there is no more risk. Moses has asked them denouncing: then what is your duty? You should also leave the tyrannical land. On the other hand, Muhammad’s friends, such as Al Muqdad, didn’t say this. Instead, they say:” We believe in you, bear witness that you were sent to spread the message of the truth, we will follow you by our hearing and sights. So move forward, O God’s prophet, we are with you. We swear by He who sent you with the truth that if you decide to dive into the sea, we will dive into it with you. No man of ours will leave you and we’re not afraid of our enemy”. 
Then, the true waiting for the relief is to stabilize honest strength, real instinct and hope that we will find good luck to be among the soldiers of Imam Al Mahdi (ajtf) army to help him make life better.
Fighting for the sake of God and Martyrdom, Al Maaref Islamic and Cultural Institution
 Surah Al Ma’ida verse 24
 The saying is for Sa’ed bin Mo’az, he said it as an answer for God’s messenger (pbuh) who consults the followers to fight the polytheist in Badr Battle. You can find it in the Prophet Biography for Ibn Hisham part 2, page 448