Assalaamu alaykum. I know that abandoning a Muslim for more than three days is haram. If i have a fight or a disagreement with someone and I do not want to be in contact with him for more than three days so that he cools down and then contact him afterwards, will I be sinful? I am only doing this so that I have a better chance to reconcile with him in this way than if I contacted him after three days.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.

The basic principle is that it is impermissible for the Muslim to abandon his fellow Muslim for more than three days - as you mentioned - except for a valid reason. The Prophet, sallallahu ‘alayhi wa sallam, said, "It is not lawful for the Muslim to desert his brother for more than three nights; they meet; so this one turns away and the other turns away, and the better one of the two is the one who greets the other first." [Al-Bukhari and others]

Abandoning for more than three days is impermissible because the motive for abandoning someone is most likely removed after three days, so it is impermissible to exceed this period except for a reason that is valid according to the Sharia, such as the case when the abandoned person is persistently committing a sin and that deserting him would help deter him from committing it.

Az-Zarqaani wrote in his commentary on Al-Muwatta', "The apparent indication of the hadeeth is that abandoning for three days is allowed, because human beings inevitably exhibit anger and bad conduct. So they are pardoned for this interval, as stated by ‘Iyaadh, because the nature of mankind is that their anger subsides after the three."

Hence, it is prohibited to forsake your fellow Muslim brother beyond three days under the pretext that you are waiting for him to calm down or have the chance to reconcile with him. It is possible that this is mere procrastination and thoughts inspired by the devil. Based on the Hadeeth, the person bears a sin for forsaking beyond three for no Sharee‘ah-acceptable reason, because this period is often enough to vent one's anger as mentioned above. Moreover, greeting puts an end to desertion. It is sufficient for you to greet him with the greeting of Salaam upon meeting him after three days to end the state of abandonment.

Al-Haafith Al-‘Iraaqi wrote, "Maalik, Ash-Shaafi‘i, and the majority of the scholars held that it is sufficient to greet the deserted person to put an end to the desertion. This is the apparent indication of the statement of the Prophet, sallallahu ‘alayhi wa sallam, '...and the better one of the two is the one who greets the other first.'" [Tarh At-Tathreeb]

As for your statement, "I do not want to be in contact with him for more than three days so that he cools down...", if this was because you did not happen to meet him or the like, then you bear no sin for that, Allah willing, because the Prophet, sallallahu ‘alayhi wa sallam, said, "They meet so this one turns away and the other turns away..."

In brief, it is impermissible for the Muslim to forsake his fellow Muslim brother for more than three (days or nights) except to realize a Sharia-acceptable interest, and he bears no sin if he does not meet him after the three days.

Allah knows best.