Sutra 3.4

त्रयमेकत्र संयमः॥४॥

trayam-ekatra saṁyamaḥ ॥4॥

trayam = three; ekatra = together; saMyamaH = samyama;

Sw. Satchidananda

"The practice of these three [dharana, dhyana and samadhi] upon one object is called samyama."

Bryant

"When these three are performed together, it is called samyama."

Taimni

"These three taken together constitute Samyama."

As we know, chapter 3 of the Yoga Sutras, known as Vibhuti Pada, is largely devoted to the attainment of supernormal powers by contemplation on a variety of objects. To attain such powers, one needs to apply all three stages of meditation practices – dharana, dhyana and samadhi – on the same object. Patanjali has given the technical name “Samyama” to the collective practice of these three stages of meditation.