The Berachot that we recite before the Shema prayer every morning begin with the Beracha of "Yoser Or U’boreh Hoshech…" The Shulhan Aruch (Orah Haim 59) notes that Halacha requires mentioning God’s creation of both light and darkness ("Yoser Or," and "U’boreh Hoshech") even during the daytime. Intuitively, we might have assumed that we should give praise to God for the creation of light during the daytime, and then give praise for darkness at nighttime. In truth, however, we give praise for both light and darkness in the morning prayer service. The Shulhan Aruch explains (listen to audio recording for precise citation) that this is necessary as a way of negating the belief in two different creators. There were some faiths that recognized the existence of separate divine beings, one which created light and another that created darkness. We must avoid even giving the appearance of subscribing to this heretical belief, and therefore we cannot mention God’s creation of light without mentioning also His creation of darkness. For this reason, we recite "Yoser Or U’boreh Hoshech" every morning, thanking the Almighty for creating both light and darkness.
Many people unfortunately recite this phrase too rapidly, and as a result they mispronounce the words. Since we recite this text each and every morning, such that it is very familiar to us, some have the tendency to recite it too quickly and slur the words, and end up reciting "Yoseror" instead of "Yoser Or." There is no such word as "Yoseror," of course, and one must therefore recite these words carefully and make a slight pause between the words "Yoser" and "Or" so that he recites the text properly. Our Sages teach that one should recite the words of prayer with the same patience, care and attention as he counts his money. Just as one counts money with special care to ensure that he does not miss a number, similarly, one must recite each and every letter and word of the Tefila with attention and patience. Each letter has great significance, and thus skipping a letter could sabotage one’s entire Tefila. Therefore, when reciting "Yoser Or," one should recite the words slowly and patiently, so that he pronounces them correctly.
