The message of “Peace to all” is not only promoted by Khwaja Sahib (R.A.) but it is a basis of Islam as well. Islam stands for the concept of peace and God is Peace.
Hazrat Abdullah (R.A) said, "When we prayed behind the Prophet ﷺ, May God bless him and grant him peace, we used to say, 'Peace upon Gabriel and Michael, peace upon so-and-so.'
"Then the Prophet ﷺ turned to us and said, 'In fact, God is peace.
So when any one of you prays, then say, "All benedictions are for God; and so are all prayers and all that is good. Peace upon you, O God. Peace upon us, and upon all genuine servants of God, “for if you say this, it will reach out to every true servant of God in the heavens and the earth; "I testify that there is nothing worthy of worship but God and that Muhammad is a servant and messenger of God."
(Attributed to the Prophet Muhammad ﷺ – Hadith) Source: Five Classics of World Religions: Vol.4 The Wisdom of the Prophet: Sayings of Muhammad.
(Selections from the Hadith) Translated by Thomas Cleary Edited by Jack Kornfield. Boston & London: Shambhala Press, 1994. Pg.3-4.