It is related that there occurred between Husain bin Ali bin abi Talib (ra) and his brother Muhammad bin Al-Hanafiyyah some differences (disagreement) and they both parted, one angry with the other. Muhammad reaches his home, took out a scroll and wrote:
In the Name of Allah, the Most Gracious Most Merciful
From Muhammad to his brother Husain:
Indeed, you have honor that is unattainable for me and superiority that i can never know. Upon receiving this scroll, wear your robe and shoes, come to me and be pleased with me. Be aware of allowing me to precede you to that virtue which you are more worthy of. And upon you is peace.
When Husain (ra) read the letter, he wore his robe and shoes, met his brother and made peace with him.
From this we can learn that one should initiate attaining virtue and hasten to seek conciliation with the one that differs with him.
Source: Gems & Jewels p.g81