Allah, The Most High, said in his Noble Book:

وَشَاوِرْهُمْ فِي الأَمْرِ فَإِذَا عَزَمْتَ فَتَوَكَّلْ عَلَىالله

And consult them in the affairs. Then when you have taken a decision, put your trust in Allah.

[3/159]

Also Allah, The Most High, said:

{وأمرهم شورى بينهم}

And who (conduct) their affairs by mutual consultation.

[42/38]

Ash-Shaykh Saalih al-Fawzaan, may Allah preserve him, said regarding the tafseer of the aforementioned verse:

“The noble verse comprises of a praise for the believers who possess these traits which include that they consult each other relating to important matters, where the right opinion is hidden, that is for the purpose of cooperating upon achieving what contains of goodness to the general and to the specific because of what it possesses of unity of the hearts and unity in word and due to what it possess of humility and gentleness to the believers…”

Al-Imaam Ibn Katheer, may Allah have mercy upon him, said regarding the explanation of the statement of Allah, The Most High:

فَاعْفُ عَنْهُمْ وَاسْتَغْفِرْ لَهُمْ وَشَاوِرْهُمْ فِى الاٌّمْرِ

So pardon them, and ask (Allah’s) forgiveness for them; and consult them in the affairs.

[3:159]

“The Messenger of Allah, alaihi as-salaatu was-salaam, used to consult his Companions about various matters, to comfort their hearts, and so they actively implement the decision they reach to…”

Also Al-Imaam al-Mufassir as-Sa’dee, may Allah have mercy upon him, said in regards to the statement of Allah:

{وأمرهم}

“Their affair, whether it be worldly or religious affairs”

{شورى بينهم}

Meaning: no one from them conceals his view/opinion from the rest in relating to a matter which concerns each other, whereas this will not occur except it being a branch of their unity and their harmony and compassion and love for each other and their strong comprehension (of affairs), that if they intend a matter which is in need of thinking and brain-storming then they come together for it and they mutually consult and examine it up until it becomes clear to them the (out-weighing) benefit, hence they take advantage of it and rush to it…”

Al-Imaam as-Sa’dee also mentioned some benefits of mutual consultation in important matters, which I mentioned below in abridge point form:

1: Consulting each other is from the acts of worship which one gets closer to Allah by.

2: It comforts the hearts of one another and removes any type of evil thought that may occur.

3: It opens ones mind and expands his level of thinking.

4: The outcome of consultation is mostly successful.

Reference: Tafseer as-Sa’dee, print: Daar Ibnil Hazm.