From the book "Operational Amplifier Speed and Accuracy Improvement" by V. Ivanov,
Verification of the biasing circuit has to be done by transient simulation, with slow rampling of the supply voltage first, followed by switching of the load current and supply voltage
What the author must have meant is that you should slowly ramp up the supplies, hold it for a while and then slowly ramp it down to zero to verify how your biasing voltages change.....
Added after 3 hours 23 minutes:
What he meant by switching the load current is that there could be a load which needs to be charged during one phase of the clock and in the other phase, it is high impedance......