Material activities are caused by the mahat-tattva’s being agitated. At first there is transformation of the modes of goodness and passion, and later — due to the mode of ignorance — matter, its knowledge, and different activities of material knowledge come into play.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
महतस्तु विकुर्वाणाद्रजःसत्त्वोपबृंहितात् । तमःप्रधानस्त्वभवद्द्रव्यज्ञानक्रियात्मकः
mahatastu vikurvāṇādrajaḥsattvopabṛṃhitāt | tamaḥpradhānastvabhavaddravyajñānakriyātmakaḥ
SB 2.5.23