Constitution of Malaysia 1957
Article 40A
(2) The Yang di-Pertuan Agong may act in his discretion in the performance of the following functions, that is to say -
(a) the appointment of a Prime Minister;
Article 43
(2) The Cabinet shall be appointed as follows, that is to say -
(a) the Yang di-Pertuan Agong shall first appoint as Perdana Menteri (Prime Minister) to preside over the Cabinet a member of the House of Representative who in his judgment is likely to command the confidence of the majority of the members of that House; and
(b) he shall on the advice of the Prime Minister appoint other Menteri (Ministers) from among the members of either House of Parliament;