If so, please provide the verses. It would also be helpful if you provide a link.
Lingam-Yoni symbol was probably adopted by the Saivites later than the Vedas. The philosophy is same as that of Vedanta.
Why is Shiva worshipped as a Lingam?
The answer is that the Saivites use the linga form to signify nameless and formless aspects of the deity.
Sages said:- 8. Everywhere the deities are worshipped only in their image. How is that Siva is worshipped both in the image and the linga?
Suta said:- 9. O sages, this question is holy and wondrous. Here the speaker is Siva Himself and not any ordinary person. 10. I shall tell you what Siva Himself had said and what I heard from my own preceptor. Siva alone is Niskala (nameless and formless) since He is identical with supreme Brahman. 11. He is also Sakala as He has an embodied form. He is both Sakala and Niskala. It is his Niskala aspect that the Linga is appropriate. 12-13. In the Sakala aspect the worship of His embodied form is appropriate. Since He has the Sakala and Niskala aspects He is worshipped both in the linga and in the embodied form by the people and is called the highest Brahman.
Shiva Purana, Vidyesvarasamhita, Chapter 5
Where does the linga form come from?
The day on which I manifested myself in the form of a column of fire is the Ardra star in the month of Marga-sirsa (November-December), O children.
He who sees me on the day of Ardra star in the month of Margasirsa in the company of Uma and worships my Linga emblem or embodied image is dearer to me than even Guha (Kartikeya)
On that auspicious day (Sivaratri) the vision alone accords ample results. If he worships too, the result cannot be adequately described.
Since I manifested myself in the form of Linga emblem in the field of battle, this place will be known as Lingasthana.
O sons, this column without root or top will henceforth be diminutive in size for the sake of the vision and worship of the world.
The Linga emblem confers enjoyment. It is the only means of worldly enjoyment and salvation. Viewed, touched or meditated upon, it wards off all future births of the living beings.
Since the Linga emblem rose high resembling a mountain of fire, this shall be famous as Ruddy (Aruna) mountain. Many holy centres will spring up here. A residence or death in this holy place ensures liberation.
Siva Purana, Vidyesvarasamhita, chapter 9.15-22
What is the philosophical meaning of the Linga?
Shiva Linga according to Shiva Purana represents an infinite tower of light and is used to represent nishkala (formless) Shiva. Linga means mark. Shiva Linga simply means a symbol of Shiva. The Yoni associated with the Shiva Linga is simply the source. Just as Vedantins have Brahman - Shakti, Sankhya has Purusha - Prakriti, Shaivism has Linga - Yoni.
The Linga is equivalent to Brahman of Vedanta. The word linga is traced to two Sanskrit roots, li meaning to dissolve and gam which means to go, to be manifested or created. The Sivanubhava Sutra 3.3 defines Linga as follows:
That in which all mobiles and immobiles enter, i.e., get dissolved, and that from which the universe is created is Linga.
Sivanubhava Sutra 3.3
There are also mukha linga or Lingas with faces. Then there are vigraha Lingas where the full form of Siva is inscribed on the Linga. The faceless Lingas are called Sthanu Linga or Linga columns which form is traced to legendary material about Shiva given in certain Puranas like Linga Purana (ch 17), the Kurma Purana (I.26.68-99) etc where Shiva appeared as a column of fire.
There is no mention in the Rig Veda or any of the other Shruti Vedic texts of the Shiva Lingam. There are, however, many references to the Shiva Lingam throughout the later Smriti
Linga and Yoni seem to be endogenous to the Indus Valley (p11, Introducing Hinduism, Rodrigues, 2006) whereas the predominate theory regarding Vedic peoples is that they came from the Caucasian area near Sintashta (the source of domesticated horses, chariots, Vedic burial rites, Indo-Iranian languages, and much of the Y-chromosome DNA of skeletal remains from the Vedic period). Thus, Sanatana Dharma is most likely a synthesis of local and Aryan religious practices. This is why linga aren't in the Vedas; initially they were only utilized by the local IVC—which left no known writings.