Reference: ad-Durr ath-Thameen fee Tarjamati Faqeehil-Ummah al-’Allaamah ibn ‘Uthaymeen – Page 228.
Shaykh ‘Abdullaah ibn ‘Abdil-’Azeez al-Ghufays narrates:
‘Whilst in the room (allocated to the Shaykh for responding to the people’s questions within al-Masjid al-Haraam, Makkah) he used to be economical in his use of the light. So when the lights were switched on there would be three or four, he would say:
“Only one or two are sufficient for us.”’