Essay "Religion Allied to Progress" http://www.ucalgary.ca/~elsegal/363_Transp/Orthodoxy/SRHirsch.html
Famous Samson Raphael Hirsch Quotes
Commentary on Genesis XXIV, 67 quoted by Joseph H. Hertz, Pentateuch, p. 87
Horeb: A Philosophy of Jewish Laws and Observances, translated by Isidor Grunfeld, London: Soncino Press, 1968, vol. II https://books.google.it/books?id=tEIIAAAAIAAJ, p. 292, sec. 415.
Essay "Religion Allied to Progress" http://www.ucalgary.ca/~elsegal/363_Transp/Orthodoxy/SRHirsch.html