Guide for the Perplexed, by Moses Maimonides, Friedländer tr. [1904], at sacred-texts.com
IT is well known that the verb yalad means "to bear," "they have born (ve-yaledu) him children" (Deut. xxi. 15). The word was next used in a
figurative sense with reference to various objects in nature, meaning, "to create," e.g. "before the mountains were created" (yulladu) (Ps. xc. 2); also, "to produce," in reference to that which the earth causes to come forth as if by birth, e.g., "He will cause her to bear (holidah) and bring forth" (Isa. Iv. 10). The verb further denotes, "to bring forth," said of changes in the process of time, as though they were things which were born, e.g., "for thou knowest not what a day may bring forth" (yeled) (Prov. xxvii. 1). Another figurative use of the word is its application to the formation of thoughts and ideas, or of opinions resulting from them: comp. "and brought forth (ve-yalad) falsehood" (Ps. vii. 14); also, "and they please themselves in the children (yalde) of strangers" (Isa. ii. 6), i.e., "they delight in the opinions of strangers." Jonathan the son of Uzziel paraphrases this passage, "they walk in the customs of other nations."
A man who has instructed another in any subject, and has improved his knowledge, may in like manner be regarded as the parent of the person taught, because he is the author of that knowledge: and thus the pupils of the prophets are called "sons of the prophets," as I shall explain when treating of the homonymity of ben (son). In this figurative sense, the verb yalad (to bear) is employed when it is said of Adam, "And Adam lived an hundred and thirty years, and begat (va-yoled) a son in his own likeness, in his form" (Gen. V. 3). As regards the words, "the form of Adam, and his likeness," we have already stated (ch. i.) their meaning. Those sons of Adam who were born before that time were not human in the true sense of the word, they had not "the form of man." With reference to Seth who had been instructed, enlightened and brought to human perfection, it could rightly be said, "he (Adam) begat a son in his likeness, in his form." It is acknowledged that a man who does not possess this "form" (the nature of which has just been explained) is not human, but a mere animal in human shape and form. Yet such a creature has the power of causing harm and injury, a power which does not belong to other creatures. For those gifts of intelligence and judgment with which he has been endowed for the purpose of acquiring perfection, but which he has failed to apply to their proper aim, are used by him for wicked and mischievous ends; he begets evil things, as though he merely resembled man, or simulated his outward appearance. Such was the condition of those sons of Adam who preceded Seth. In reference to this subject the Midrash says: "During the 130 years when Adam was under rebuke he begat spirits," i.e., demons; when, however, he was again restored to divine favour "he begat in his likeness, in his form." This is the sense of the passage, "Adam lived one hundred and thirty years, and he begat in his likeness, in his form" (Gen. v. 3).