Yoga Sutra

Sadhana Pada: Sutra 2.7

सुखानुशयी रागः॥७॥

sukha-anuśayī rāgaḥ

sukha=  pleasure

anuśayī = the immediate attraction to, causes

rāgaḥ= attachment, binding

Pleasure causes attraction

Pleasure is the root cause of attachment. It makes an addiction. Pleasure is one modification of the mind. It leads to another modification: attachment. For instance, you have pleasure in the taste of a particular food. Oftentimes, you seek to enjoy that taste. It is an attachment to that state. If your mind has the modification of pleasure in anything,  you are attached to that. You remember that pleasure. You feel pain when you are not having that. It makes an attachment.

It creates a passion on your part when you perceive pleasure or recollect it.

Commentary by Maharishi Vyasa
Passion is that dwells upon pleasure

The desire or passion is the yearning after pleasure or its means. It is preceded by the recollection or the remembrance of the pleasure on the part of the one who has acquaintance with or the experience of the pleasure.

Commentary by Swami Vivekananda
Attachment is that which dwells on pleasure

We find pleasure in certain things, and the mind, like a current, flows towards them, and that, following the pleasure center, as it were, is attachment. We are never attached to anyone in whom we do not find pleasure. We find pleasure in very queer things sometimes, but the definition is just the same; wherever we find pleasure, there we are attached.

Commentary by Sri Osho
ATTRACTION, AND THROUGH IT, ATTACHMENT, IS TOWARDS ANYTHING THAT BRINGS PLEASURE.

Sri Osho gives a commentary for Sutra 2.7 and 2.8 together. Refer to Sutra 2.8.