During his retirement speech in Haarlem in 1940, Rabbi De Vries said:

The words spoken by De Vries were a rabbinical response to the German occupation of the Netherlands. They illustrate one of the Jewish reactions to fears about the persecution that was expected to follow the German invasion of the country.

After the capitulation of the Dutch army in May 1940, the Germans imposed their regime in the Netherlands with competing elements from their army, intelligence, security and police services. Dutch National Socialists also strived to gain power. The Dutch civil service, headed by Secretaries General, was mostly left intact and implemented German decrees. The Dutch population at large remained unclear about the intentions of the occupiers. Initially, in an effort to gain the trust of the Dutch, the Germans allowed life to resume its seemingly normal course. In most people's eyes the occupiers seemed to act correctly. There were several manifestations of continued support for the royal family (for example, on the celebration of the birthday of the queen's son-in-law, Prince Bernhard, in June 1940), but only small-scale acts of resistance took place. However, for Jews the outlook remained bleak. The expected pogroms failed to materialise, but occasionally German soldiers and Dutch National Socialists attacked synagogues and persons who appeared to be Jews. Well-known men such as the Socialist and trade union leader Polak were arrested and imprisoned. The occupying authorities also announced decrees, some of which especially affected Jews, such as the ban on ritual slaughter.