Adam Clarke on John 16:12

Ye cannot bear them now - In illustration of these three points, Christ had many things to say; but he found that his disciples could only bear general truths; yet, in saying what he did, he sowed the seeds of the whole system of theological knowledge, and heavenly wisdom, which the Holy Spirit of this truth afterwards watered and ripened into a glorious harvest of light and salvation, by the ministry of the apostles. Dr. Lightfoot supposes that the things which the apostles could not bear now were such as these:

1. The institution of the Christian Sabbath, and the abolition of the Jewish.

2. The rejection of the whole Jewish nation, at the very time in which they expected to be set up and established for ever.

3. The entire change of the whole Mosaic dispensation, and the bringing the Gentiles into the Church of God.