सजातीयप्रवाहश्च विजातीयतिरस्कृतिः ।नियमो हि परानन्दो नियमात्क्रियते बुधैः ॥ १०५ ॥
In plain words
One kind of thought flowing on unbroken, every other kind turned away: that is niyama, and it is supreme bliss itself. The wise keep at it without a break.
Close to the Sanskrit
And the flow of what is of the same kind, the setting aside of what is of another kind — this indeed is niyama, supreme bliss; it is practiced constantly by the wise.