William Law, A Serious Call to a Devout and Holy Life.
If our blessed Lord used to pray early before day; if He spent whole nights in prayer; if the devout Anna was day and night in the temple; if Paul and Silas at midnight sang praises unto God; if the primitive Christians, for several hundred years, besides their hours of prayers in the daytime, met publicly in the churches at midnight to join in psalms and prayers; is it not certain that these practices showed the state of their heart? Are they not so many plain proofs of the whole turn of their minds?
William Law, A Serious Call to a Devout and Holy Life.