1) Each of the morning blessings were instituted from a pleasure derived from the world, as it is forbidden to have benefit from this world without a blessing. (Shulchan Aruch and Mishne Berurah 24)
2) The explanation of the blessing which starts with “Hanosein lasechvi binah…”, is that it refers to the heart of a person, which distinguishes between day and night. There is, however, another explanation that it refers to the rooster (which is called “sechvi” in certain languages,) which also distinguishes between day and night. Chazal therefore instituted that we make this blessing when we hear the rooster crowing. If one does not hear the rooster, one still makes this blessing. (Mishne Berurah ibid)
